Fan Control Device and Fan Control Method and Cooling System Thereof

ABSTRACT

The present invention discloses a fan control device for controlling a fan. The fan control device includes a barometer, for measuring an atmospheric pressure of an operating environment of the fan, and a maximum rotating speed setting unit, for setting a maximum operable rotating speed of the fan according to the atmospheric pressure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fan control device and fan control method and cooling system thereof, and more particularly, to a fan control device and fan control method and cooling system thereof capable of increasing a maximum operable rotating speed of the fan under a high elevation environment, to enhance fan efficiency and reduce cost.

2. Description of the Prior Art

An air cooling system is commonly used in an electronic package cooling system for considerations of cost and reliability. However, since the cooling capability of the air cooling system is highly related to the air density (the air cooling system performs cooling by a heat convection of air molecules), compared the cooling capability of the air cooling system of an environment of low elevation and high air density, with that under an environment of high elevation (e.g. above 3000-4000 feet) and low air density decreases significantly. Therefore, other than cooling operations under the low elevation, design of cooling operations of the current cooling system under the high elevation should also be considered, to meet practical requirements, i.e. the design of the current cooling system needs to consider drawbacks of the reduced cooling capability and the reduced heat convection capability due to the reduced air density

In such a situation, the conventional cooling system generally increases the number of fans, or is over-designed with a fan of higher performance (i.e. compared with a fan generally utilized for the low elevation environment, the fan of higher performance can be drove with higher current to achieve higher rotating speed for cooling), to meet the cooling requirements under the high elevation environment, or even reduces system performance to reduce heat, to adapt to performance loss of the fan under the high elevation environment.

However, increasing the number of the fans for the high elevation requirements may increase the cost, and over-designing the fan with higher performance may increase the cost and can not make full use of the fan of higher performance under the low elevation environment, which causes waste. Thus, there is a need for improvement of the prior art.

SUMMARY OF THE INVENTION

It is therefore an objective of the present invention to provide a fan control device and fan control method and cooling system thereof capable of increasing a maximum operable rotating speed of the fan under a high elevation environment, to enhance fan efficiency and reduce the fan cost.

The present invention discloses a fan control device for controlling a fan. The fan control device includes a barometer, for measuring an atmospheric pressure of an operating environment of the fan; and a maximum rotating speed setting unit, for setting a maximum operable rotating speed of the fan according to the atmospheric pressure.

The present invention further discloses a fan control method for controlling a fan. The fan control method includes measuring an atmospheric pressure of an operating environment of the fan; and setting a maximum operable rotating speed of the fan according to the atmospheric pressure.

The present invention further discloses a cooling system. The cooling system includes a fan; and a fan control device for controlling the fan. The fan control device includes a barometer, for measuring an atmospheric pressure of an operating environment of the fan; and a maximum rotating speed setting unit, for setting a maximum operable rotating speed of the fan according to the atmospheric pressure.

These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a cooling system according to an embodiment of the present invention.

FIG. 2 is a detailed schematic diagram of a fan control process according to an embodiment of the present invention.

DETAILED DESCRIPTION

Please refer to FIG. 1, which is a schematic diagram of a cooling system 10 according to an embodiment of the present invention. As shown in FIG. 1, the cooling system 10 includes a fan 102 and a fan control device 104. The fan control device 104 can control the fan 102, and include a barometer 106 and a maximum rotating speed setting unit 108. In short, the barometer 106 can measure an atmospheric pressure AP of an operating environment of the fan 102, and the maximum rotating speed setting unit 108 can set a maximum operable rotating speed MORS of the fan 102 according to the atmospheric pressure AP.

Since air density is low under a high elevation environment, an air resistance for the fan 102 is reduced as well, and the fan 102 can have a higher rotating speed when the fan 102 consuming the same energy as under a low elevation environment. In such a situation, the fan control device 104 can set the maximum operable rotating speed MORS of the fan 102 as a predefined low elevation maximum operable rotating speed DLMORS which the fan 102 can tolerate under a low elevation environment (i.e. a rotating speed achieved by the fan 102 when receiving a maximum tolerable energy under the low elevation environment), and the fan control device 104 sets the maximum operable rotating speed MORS of the fan 102 as a high elevation maximum operable rotating speed HMORS which the fan 102 can sustain under the high elevation environment (i.e. the rotating speed achieved by the fan 102 when receiving the maximum sustainable energy under the high elevation environment), wherein the high elevation maximum operable rotating speed HMORS is greater than the predefined low elevation maximum operable rotating speed DLMORS. As a result, since the fan control device 104 can measure the atmospheric pressure AP of the operating environment of the fan 102, and increase the maximum operable rotating speed MORS of the fan 102 to enhance performance when under the high elevation environment, the present invention does not need to increase the number of fans or over-design a fan with higher performance, so as to reduce cost.

Please refer to FIG. 2, which is a detailed schematic diagram of the fan control process 20 according to an embodiment of the present invention. The fan control process 20 is utilized in the fan control device 104, to set the maximum operable rotating speed MORS of the fan 102. The fan control process 20 includes following steps:

Step 200: Start.

Step 202: Measure the atmospheric pressure AP of the operating environment of the fan 102. If the atmospheric pressure AP is greater than a predefined atmospheric pressure DAP, go to Step 204; otherwise, go to Step 206, wherein an operating current of the fan 102 is an operating current Ia when the fan 102 is driven.

Step 204: Determine that the fan 102 operates in a low elevation environment, and set the maximum operable rotating speed MORS of the fan 102 as the predefined low elevation maximum operable rotating speed DLMORS, wherein the operating current Ia of the fan 102 is a maximum operating current Id when the fan 102 is driven in the predefined low elevation maximum operable rotating speed DLMORS.

Step 206: Determine that the fan 102 operates in a high elevation environment, and increase the maximum operable rotating speed MORS of the fan 102.

Step 208: Determine whether the operating current Ia is less than the maximum operating current Id. If yes, go to Step 206; otherwise, go to Step 210.

Step 210: Set the maximum operable rotating speed MORS of the fan 102 as the high elevation maximum operable rotating speed HMORS when the operating current Ia of the fan 102 is equal to the maximum operating current Id, wherein the high elevation maximum operable rotating speed HMORS is the rotating speed of the fan 102 driven with the maximum operating current Id.

According to the fan control process 20, the fan control device 104 measures the atmospheric pressure AP of the operating environment of the fan 102 first, and if the atmospheric pressure AP is greater than the predefined atmospheric pressure DAP, the fan control device 104 determines that the fan 102 operates in the low elevation environment, and thus sets the maximum operable rotating speed MORS of the fan 102 as the predefined low elevation maximum operable rotating speed DLMORS, and the predefined low elevation maximum operable rotating speed DLMORS is the rotating speed of the fan 102 when the operating current Ia of the fan 102 is the maximum operating current Id (i.e. the maximum tolerable energy of the fan 102). As a result, since the maximum operable rotating speed MORS of the fan 102 under the low elevation environment can be set as the rotating speed achieved by the fan 102 when receiving the maximum tolerable energy, the performance of the fan 102 is fully utilized.

On the other hand, if the atmospheric pressure AP is less than the predefined atmospheric pressure DAP, the fan control device 104 determines that the fan 102 operates in the high elevation environment, and thus sets the maximum operable rotating speed MORS of the fan 102 to be greater than the predefined low elevation maximum operable rotating speed DLMORS (since the air density is low under the high elevation environment, the fan 102 can achieve a higher rotating speed with the same maximum tolerable energy). At this moment, the fan control device 104 can increase the maximum operable rotating speed MORS of the fan 102 first, and determine whether the corresponding operating current Ia is less than the maximum operating current Id. If the operating current Ia is less than the maximum operating current Id, the fan control device 104 continues to increase the maximum operable rotating speed MORS of the fan 102 until the operating current Ia of the fan 102 is equal to the maximum operating current Id, and the maximum rotating speed setting unit 108 sets the maximum operable rotating speed MORS of the fan 102 as the high elevation maximum operable rotating speed HMORS, wherein the high elevation maximum operable rotating speed HMORS is the rotating speed of the fan 102 when the maximum rotating speed setting unit 108 drives the fan 102 with the maximum operating current Id (i.e. the maximum tolerable energy of the fan 102) under the high elevation environment. In such a situation, after deriving the high elevation maximum operable rotating speed HMORS by above operations, in a next operation, if the fan control device 104 measures the atmospheric pressure AP is less than the predefined atmospheric pressure DAP again and determines that the fan 102 operates in the high elevation environment again, the maximum operable rotating speed MORS can be directly set as the high elevation maximum operable rotating speed HMORS, to reduce a time consumed by loop determination, and enhance the fan efficiency. As a result, since the air density is low under the high elevation environment, the maximum operable rotating speed MORS of the fan 102 can be increased and set as the rotating speed achieved by the fan 102 when receiving the maximum tolerable energy, and thus performance of the fan 102 adapted to the low elevation environment can be fully utilized, to meet requirement of the high elevation environment (i.e. the performance of the fan 102 can be fully utilized under the low elevation environment or high elevation environment) without utilizing the fan of higher performance as the prior art.

Noticeably, the main spirit of the present invention is to measure the atmospheric pressure AP of the operating environment of the fan 102, to increase the maximum operable rotating speed MORS of the fan 102 when the fan 102 is under the high elevation environment, to enhance the performance, so as to reduce cost without increasing the number of the fans or over-designing the fan with higher performance. Those skilled in the art can make modifications or alterations accordingly. For example, the above embodiment sets the maximum operable rotating speed MORS of the fan 102 after determining the fan 102 operates under the low elevation environment or high elevation environment with the barometer 106. In other embodiments, the fan control device 104 does not include the barometer 106, and increases the maximum operable rotating speed MORS of the fan 102 according to whether the operating current Ia is less than the maximum operating current Id (i.e. the maximum operable rotating speed MORS is the rotating speed corresponding to the maximum operating current Id in different environments), but the operating current Ia and the maximum operating current Id are compared continuously, causing system unstable.

In the prior art, increasing the number of the fans for requirement the high elevation environment may increase cost, and over-designing the fan with higher performance may increase the cost and not fully utilize the fan under the low elevation environment, causing waste. In comparison, the present invention can measure the atmospheric pressure AP of the operating environment of the fan 102, to increase the maximum operable rotating speed MORS of the fan 102 when under the high elevation environment, to enhance performance, and thus reducing cost without increasing the number of the fans or over-designing the fan with higher performance.

Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims. 

What is claimed is:
 1. A fan control device for controlling a fan, comprising: a barometer, for measuring an atmospheric pressure of an operating environment of the fan; and a maximum rotating speed setting unit, for setting a maximum operable rotating speed of the fan according to the atmospheric pressure.
 2. The fan control device of claim 1, wherein the maximum rotating speed setting unit sets the maximum operable rotating speed of the fan as a predefined low elevation maximum operable rotating speed when the atmospheric pressure is greater than a predefined atmospheric pressure; wherein an operating current of the fan is a maximum operating current when the maximum rotating speed setting unit drives the fan in the predefined low elevation maximum operable rotating speed.
 3. The fan control device of claim 1, wherein the maximum rotating speed setting unit sets the maximum operable rotating speed of the fan to be greater than a predefined low elevation maximum operable rotating speed when the atmospheric pressure is less than a predefined atmospheric pressure.
 4. The fan control device of claim 3, wherein the maximum rotating speed setting unit increases the maximum operable rotating speed of the fan until an operating current of the fan is equal to the maximum operating current; wherein the maximum rotating speed setting unit drives the fan in a high elevation maximum operable rotating speed with the maximum operating current, and sets the maximum operable rotating speed of the fan as the high elevation maximum operable rotating speed.
 5. The fan control device of claim 4, wherein the maximum rotating speed setting unit directly sets the maximum operable rotating speed of the fan as the high elevation maximum operable rotating speed when the atmospheric pressure is less than the predefined atmospheric pressure again.
 6. A fan control method for controlling a fan, comprising: measuring an atmospheric pressure of an operating environment of the fan; and setting a maximum operable rotating speed of the fan according to the atmospheric pressure.
 7. The fan control method of claim 6, wherein the step of setting the maximum operable rotating speed of the fan according to the atmospheric pressure comprises: setting the maximum operable rotating speed of the fan as a predefined low elevation maximum operable rotating speed when the atmospheric pressure is greater than a predefined atmospheric pressure; wherein an operating current of the fan is a maximum operating current when driving the fan in the predefined low elevation maximum operable rotating speed.
 8. The fan control method of claim 6, wherein the step of setting the maximum operable rotating speed of the fan according to the atmospheric pressure comprises: setting the maximum operable rotating speed of the fan to be greater than a predefined low elevation maximum operable rotating speed when the atmospheric pressure is less than a predefined atmospheric pressure.
 9. The fan control method of claim 8, wherein the step of setting the maximum operable rotating speed of the fan to be greater than the predefined low elevation maximum operable rotating speed comprises: increasing the maximum operable rotating speed of the fan until an operating current of the fan is equal to a maximum operating current; wherein the maximum operating current drives the fan in a high elevation maximum operable rotating speed, and sets the maximum operable rotating speed of the fan as the high elevation maximum operable rotating speed.
 10. The fan control method of claim 9, further comprising: setting the maximum operable rotating speed of the fan as the high elevation maximum operable rotating speed directly when the atmospheric pressure is less than the predefined atmospheric pressure again.
 11. A cooling system, comprising: a fan; and a fan control device for controlling the fan, comprising: a barometer, for measuring an atmospheric pressure of an operating environment of the fan; and a maximum rotating speed setting unit, for setting a maximum operable rotating speed of the fan according to the atmospheric pressure.
 12. The cooling system of claim 11, wherein the maximum rotating speed setting unit sets the maximum operable rotating speed of the fan as a predefined low elevation maximum operable rotating speed when the atmospheric pressure is greater than a predefined atmospheric pressure.
 13. The cooling system of claim 11, wherein an operating current of the fan is a maximum operating current when the maximum rotating speed setting unit drives the fan in the predefined low elevation maximum operable rotating speed; wherein the maximum rotating speed setting unit sets the maximum operable rotating speed of the fan to be greater than a predefined low elevation maximum operable rotating speed when the atmospheric pressure is less than a predefined atmospheric pressure.
 14. The cooling system of claim 13, wherein the maximum rotating speed setting unit increases the maximum operable rotating speed of the fan until an operating current of the fan is equal to a maximum operating current; wherein the maximum operable rotating speed of the fan is the high elevation maximum operable rotating speed.
 15. The cooling system of claim 14, wherein the maximum rotating speed setting unit directly sets the maximum operable rotating speed of the fan as the high elevation maximum operable rotating speed when the atmospheric pressure is less than the predefined atmospheric pressure again. 